1. Field of the Invention
This invention relates to a cell-free process for producing the antibiotic deacetoxycephalosporin C from isopenicillin N, LLD or their derivatives.
2. The Prior Art
Isopenicillin N is a water soluble .beta.-lactam antibiotic having the formula: ##STR2## The aminoadipyl side chain is in the L-configuration in isopenicillin N. Penicillin N, also an effective antibiotic, has a structure identical to isopenicillin N except that the aminoadipyl side chain is in the D-configuration. Penicillin N and isopenicillin N have a number of properties in common but differ in their antimicrobial activity toward certain classes of microorganisms.
Deacetoxycephalosporin C (hereinafter referred to as DACPC) is useful as an antibiotic as such or as a starting compound for the production of cephalosporin antibiotics, such as cephalexin. DACPC is shown by the following formula: ##STR3##
Cell-free syntheses of penicillins and the related antibiotic cephalosporins are known in the art. A cell-free cephalosporin synthesis, corresponding to step (3) in the reaction sequence of the present invention, is disclosed in U.S. Pat. No. 4,178,210 entitled "Acellular Synthesis of Cephalosporins", issued Dec. 11, 1979 to A. L. Demain et al. In U.S. Pat. No. 4,178,210 Demain et al teach that the process disclosed therein was successful in converting only the D-form, penicillin N, to a cephalosporin compound using the reactive system disclosed therein. Thus to utilize the teachings of U.S. Pat. No. 4,178,210 to convert isopenicillin N to a cephalosporin, a suitable process for converting isopenicillin N to its D-form isomer, penicillin N, must first be devised.
Accordingly an object of the present invention is to provide an integrated cell-free process for producing a cephalosporin compound from isopenicillin N or LLD.
These and other objects and features of the invention will be apparent from the following description of the preferred embodiments.